The invention relates to underwater connectors particularly useful for making up and breaking electrical and/or fluid connections while under water, inter alia at great depths and without attendance by divers.
During recent years, oil wells have been drilled and operated from the bottom of the sea at depths far below those where divers can operate. However, control or monitoring electric circuits and hydraulic circuits have to be provided between a surface vessel or platform and a stationary structure permanently disposed on the bottom, such as an oil well. The cables, ducts and control units carried by the stationary structure have to be periodically connected and disconnected, for instance due to emergency conditions or when the surface vessel has to move to another place.
To solve this problem, remote-control or master-slave manipulators have been used. However, conventional manipulators mounted on submarines or remote-control robots cannot perform some of the operations that divers frequently carry out when the depth does not exceed 100.degree. meters. Beyond that depth, a module or pod suspended from a cable should be used; it should be designed for automatic connection and locking to the stationary structure, the pod carrying one half of the or each connector whereas the other half is borne by the stationary structure.
Such connectors should fulfil stringent requirements, particularly if used in tropical waters. Exposure of the contact elements to sea water results in corrosion and fouling, so that the elements rapidly become defective in operation if exposed to water. In the case of multiple electric connectors, the presence of sea water in the connector results in short-circuits or, at least, in electric leaks. Various attempts to overcome these difficulties have already been tried, inter alia by isolating the connecting elements from sea water by an oil body occupying a chamber closed by a diaphragm which is torn or perforated during coupling. In practice, however, this method can be applied only to that part of the connector which is connected to the ship and can be lifted back to the ship in order to replace the oil and diaphragm after each uncoupling operaton. It has also been proposed to protect the contact regions with a thick layer of elastomer which, during coupling, is perforated by the contact elements, which are given a suitable shape. However, after a few coupling and uncoupling operations, the elastomer ceases to operate properly. In some electrical connectors (U.S. Pat. No. 3.729,699), the electrical contacts of the female part are protected against water by a dummy piston until contact occurs. On the other hand, the contacts of the male part are immersed until connection has occured and are consequently subject to corrosion and fouling. A number of other prior art connectors have been designed and disclosed for fluid lines (see for instance U.S. Pat. Nos. 2,819,912, 2,350,681, 3,324,943 and 3,675,713 and French Pat. Nos. 1,184,169 and 1,349,497) and/or electric lines (see for instance U.S. Pat. Nos. 3,946,805, 3,839,608 and 3.339,632) but in none of them the connecting surfaces or contact are completely protected.
It is an object of the invention to provide an improved connector for underwater use which overcomes the above as well as other environmental problems. It is another object to provide a connector whose connecting elements are kept out of contact with water except during coupling and uncoupling and which may be remotely and automatically operated.
To this end, there is provided a connector comprising a female part and a male part, the female part being carried by a stationary structure and the male part being carried by a module or pod which can be moved by moving means towards and from the stationary structure in an engagement direction, typically vertically, wherein:
the female part comprises a bearing member provided with at least one passage parallel to the engagement direction, a bearing end portion and at least one female connecting element in said passage, terminating in a bearing portion; and a sealing bush rectilinearly movable along said passage in the bearing member, between a retracted position and an advanced position towards which it is urged by a return spring and in which it covers the connecting element;
the male part comprises a bearing member likewise formed with at least one passage parallel to the engagement direction, the end part of the bearing member being adapted to be applied in substantially sealing-tight manner against the previously-mentioned bearing portion and to centre the two parts relative to one another and has a plunger reciprocably received in said passage, and the side wall of which is provided with at least one connecting element for cooperating with the connecting elements of the female part, the bearing component of the male part being movable with respect to the plunger between an advanced position, towards which it is urged by a spring and in which it bounds a chamber filled with a hydraulic fluid protecting the connecting elements, and a retracted position in which the contact elements project from the bearing member; and
the moving means are adapted to move the bearing member of the female part and the plunger of the male part towards one another by compressing the return springs until the connection is made, and then to hold the male and female parts in connected condition.
In the case of an electric connector, the bush typically is a second plunger of electrically insulating material and having a diameter equal to that of the plunger of the male part, the second plunger being slidably mounted in the bearing component of the female part, and the connecting elements of the second plunger comprising annular electric contacts connected to a water-tight output connection of the male part of the connector.
The bearing member of the male part may be slidably mounted in a cylinder secured to a plate which also bears the plunger of the male part and, in cooperation with the cylinder, bounds an inner chamber in which the male connecting elements are immersed when the bearing member is in the extended position, the bearing member also being slidable in an annular outer chamber communicating with the inner chamber, the variations in volume of the outer chamber compensating those of the inner chamber when the bearing member moves in the cylinder.
In a fluid connector, the junction component of the female part typically is a channel opening radially into the passage via a mouth which is covered by the bush when the latter is in the retracted position, whereas the plunger of the male part has a duct which opens on to the side wall of the plunger via a mouth which, after coupling, is opposite the mouth of the channel of the associated member of the stationary part, the mouths being straddled by seals.
A plurality of connectors for hydraulic fluid and electric connectors can be associated with a platform and pod. One part of each connector will be borne by the stationary platform and the other part by the module or pod suspended from a cable and provided with guidance and approach means. The connector is coupled by lowering the pod towards the platform after positioning the pod over the stationary platform.
The invention will be better understood from the following description of embodiments thereof, given by way of non-limitative examples.